SQL read replicas do support point-in-time recovery

[Christopher de Vidal]

This comment is about the TD practice exams for Google Certified Associate Cloud Engineer. I failed this question, but I do not believe the answer that was marked correct is in fact correct.

“You are working for a finance company and are assigned to configure a relational database solution on Google Cloud Platform to support a small set of operational data in a particular geographical location. Your company requires the database to be highly reliable and supports point-in-time recovery while minimizing operating costs. What should you do?”

Since read replicas 1.) make the database highly reliable and 2.) can only be enabled with binary logging, I chose this answer: “Choose Cloud SQL (MySQL) and select the create failover replicas option.”

And Google says, “Before you can create a read replica of a primary Cloud SQL instance, the instance must meet the following requirements: Binary logging must be enabled which requires point-in-time recovery to be enabled.”

https://cloud.google.com/sql/docs/mysql/replication#requirements

However, the answer marked correct is “Choose Cloud SQL (MySQL) and verify that the enable binary logging option is selected.”

While that indeed does enable point-in-time recovery, I would not say it is “highly reliable” as the question demands; It is a single instance.

Per Google’s own documentation (above), a read replica 1.) makes the database highly reliable and 2.) has binary logging by default.